The goal of the Participant Core is to ensure and optimize the recruitment and retention of participants for studies of balance and aging. Successful recruitment of older persons for study participation is an essential, core function for our research. Investigators at the University of Pittsburgh have established successful methods for recruitment older adults into a full range of ongoing and completed studies of older persons, including large epidemiological cohorts, clinical trials and mechanistic investigations. This collective expertise has developed in an environment of extensive cross-departmental collaboration. The Core will provide centralized access to this expertise, through a series of recruitment training seminars as well as individual consultation. The Core will provide information regarding 11 participating studies with measures of mobility and balance that are available for add-on supplements. New participating studies can be added in the future. The Core provides access to four main resources for new recruitment, a health care based system (CRPRS), a primary care network (PRONET), volunteer resources and the geriatric services programs. Each specific has strengths for specific types of studies. The Participant Core will provide consultative direction and efficient access to these resources for new pilot and externally funded studies.